Method of forming return bends



Sept 9, 1930. J. E. TRAINER ET AL METHOD OF FORMING RETURN BENDS Filed Dec. 27, 1928 Patented se a- 9, 1930 :UNITED STATES. BATE NT orries minus mm nun rvnn 1.." Lmefvmn, or nnnnnnron, .onro, nssrenons no man mn'ooox a wrnoox comm, or BAYONNE, NEW many, A conronarzon or new man amnion or romaine nnrunn :emms

Application flled December 27, 1928. Serial No. 328,822.

This invention relatesto a novel and i'm proved method of makingreturn bends. It

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method being will be best understood from the following description and the. accompanying drawing.-

In the drawing, in which we have shown certain selected methods by which the invention maybe practised:

Fig. 1 is a longitudinal sectional view through the blank from which the bend is to be made, and illustrating one step in the method of forming the same.

Figs. '2, 3, t and 5.are views corresponding to Fig. 1, and showing other methods by which the bend may be formed, the preferred shown in Fi 5. I

In practicing the invention, a solid bar is formed, preferably with integral flanges at the ends thereof, as'described and claimed in the copeniding application of Thomas Collins, Serial N 0. 322,123, filed November 27, 1928. By the term bar we 'do not intend to limit ourselves to any one cross-sectional form of stock, although referably the stock is in the form of a cylin rical bar from which a hollow lindrical tube may be formed.

Re erring now to Fig. '1, we have shown therein a as 1 having inte al flanges 2 formed thereon. This bar is t en preferably bored'longitudinally thereof to form a bbre 3.. By the term boring we do not intend; to limit ourselves to any particular method'ot forming the hole as this hole may be made by boring, drilling orthe like. The bore 3 is preferably formed eceentric'ally of the bar, as plainly shown in Fig. 1, the wall 4.- being thicker than the wall 5, and the bore being substantially warallel to'the longitudinal axis ofthe bar. e bored stock is. then bent to form the return bend, the wall 5 being disposed on the concave side of the bend and the wall t on the convex side thereof, Suitable holes may then. be drilled through the flanges, it desired, in order to secure the bend to adjoining tubes or the like.

In l ig. 2 we have shown another method of practicin the invention, in which the bore through t a bar is formed of two portions 6 tions of the an inspection 0 portion 8 of metal is provided in one wall and a thinner wall 9 isprovided opposite the portion 8. The-stock may then be bent in such a way that the excess metal at 8 will occur on the convex or outer side of the bend.

In Fi 3 is shown still another manner'in which t e invention may be practiced. .In 7

this form the bore 3 is substantiall coaxial with the axis of the bar, and the thih wall is "provided byremoving metal at 10 on what isv to be the concave side of the bend. This leaves more metal at the portions 11 which are not bent to the same degree as the middle portion of the stock.

In Fig. 4. 2s shown another way of achieving substantially the same results as shown in Fig. 3. In this form the bar is first bent adjacent its middle onl so as to form a part 12 with more metal t an is foundat 13 die The. end por- I ar are not bent. The bore 3 is then formed and the result willbe an excess of metal at 12 over what is found diametrically opposite at 13. Then, when the bend is formed, the part 12 will be the convex portion and the part 13'will be the concave ortion.

- In Fi 5 isshown the preferre form, in which t e entire length of the bar is bent metrically opposite thereto.

slightly and substantially nm'forml and.

then the bore.3 is formed as astraig t hole extending longitudinally of the bar. This results in an excess of metal at 14 and a smallor amount diametrically opposite thereto at 15. The thickness of the wall formed b the bore 3 gradually approaches a uniform t 'ckness at the flanges 2, as will be evident from Fig. 5. The bar is then bent to the form shown in dot anddash lines in this figure, to form the return bend, and when in this form the thickness of the wall will be substantially uniform throughout the len 11 of the bend, the excess metal at it bein istributed throughout the length of the and the relatively thin portion 15 becoming thicker because of the short side at the bar. We claim V 1. The method of forming a return bend which comprises boring a hole longitudinally through a bar, with more metal on one side at the hole than on the other, and so bend which comprises forgin a bar with a flange on the end thereof, boring a hole longitudiing the bored bar that the side with less metal will form the concave side of the bend.

2. The method of forming a return bend nally therethrough with more metal on one side of the hole than on the other, and then bending the bored bar so that the side with less metal will form the concave side of the bend. r

3. The methodof forminga return bend which comprises bendin a solid bar and then borin a straight hole ongitudinally-of the bar w ereby more metal will be disposed on one side of the hole than on the other, and

so bending thebored bar that the side with less metal will form the concave side of the bend.

' 4. The method of formin a return bend which comprises bending a so id bar uniformly for substantially its entire length, boring a strai ht hole therethrough longitudinally thereo whereby more metal will be, disposed on one side of said hole than on the other, and then bending the bored bar so that the side with less metal will form the concave side of the bend.

, 5. The method of forming a return bend which com rises boring ahole longitudinally of a solid ar with the axis of the bore eccentric to at least a portion of the axis of the bar, whereby more metal is disposed on' one side of the hole than on the other, and then so bending the bored bar that the side with less metal will form the concave side of the bend.

JAMES E. TRAINER. IVAR L. LANGVAND. 

